(1) Field of the Invention
The present invention relates to a thermoplastic resin or elastomer composition which has an excellent paint adhesion and an excellent bondability to a metal or the like and which is excellent in the rubbery elasticity, moldability and heat resistant, and also to a laminate comprising a layer of said thermoplastic elastomer and a polyurethane layer.
More particularly, the present invention relates to a thermoplastic resin or elastomer composition formed by dynamically heat-treating (a) a peroxide-crosslinkable olefin type copolymer rubber and/or (b) an olefin type plastic, and one of (c) an unsaturated carboxylic acid or a derivative thereof and (d) a monomer containing at least one amino group or a blend of the components (c) and (d) in the presence of an organic peroxide, or by blending under heating the component, not subjected to the above-mentioned dynamic heat treatment, of said components (c) and (d) with the thermoplastic resin or elastomer formed by said dynamic heat treatment, and also to a laminate comprising a layer of a thermoplastic elastomer formed by blending (d) a monomer containing at least one amino group with a thermoplastic elastomer composition formed by dynamically heat-treating the components (a), (b) and (c) in the presence of an organic peroxide, and heat-treating the resulting blend, and a layer of a polyurethane.
(2) Description of the Related Art
It has been known that a thermoplastic elastomer is a cured rubber substitute of the energy-saving and resource-saving type.
As the thermoplastic elastomer of this type, there is known, for example, an olefin type thermoplastic elastomer composed mainly of an ethylene/propylene/uncojugated diene copolymer rubber. Although this elastomer is excellent in performances of the thermoplastic elastomer, the paint adhesion and the bondability to various resins or metals are insufficient, and therefore, the application range of this thermoplastic elastomer is extremely restricted.
A trial has been made to improve the bondability of this thermoplastic elastomer by modifying the above-mentioned rubber component with maleic anhydride or the like. However, in this case, characteristics such as the rubbery elasticity and moldability are drastically degraded, though the bondability is improved.
Even at the present, the paint adhesion and the bondability to various resins or metals are similarly insufficient in thermoplastic resins such as polyolefins.
Namely, a thermoplastic resin or elastomer which is excellent in not only such characteristics as the rubbery elasticity and moldability but also the paint adhesion and the bondability to various resins and metals is not known.
A polyvinyl chloride sheet having on the surface a leather pattern formed by embossing the surface and boarding the embossed surface has been heretofore used for interior automotive trims such as a floor, a wall and a ceiling.
However, since a plasticizer is incorporated in polyvinyl chloride per se, this polyvinyl chloride sheet is defective in that the surface becomes soft and sticky, and by evaporation of the plasticizer, the sheet is made rigid or the atmosphere in an automobile becomes blurred.
A laminate formed by backing a polyvinyl chloride sheet with a formed layer and, if necessary, further with a resin aggregate layer has been used instead of a single-layer sheet of polyvinyl chloride.
This laminate is prepared through the following steps.
(1) Soft polyvinyl chloride is calendered to form a sheet.
(2) A mixture of a polyol and a polyisocyanate is coated on the surface of this sheet and a urethane treatment is carried out to attain a delustering effect.
This delustering treatment is performed to prevent the sheet surface from becoming lustrous at the heat-molding step (7) described hereinafter.
(3) The sheet is subjected to an embossing treatment to form a boarded leather pattern on the surface.
(4) The back surface of the sheet having the embossed surface is subjected to a flame treatment and is molten, and a sheet of a polyurethane foam separately supplied is press-bonded to the molten back surface of the sheet by means of a roll.
(5) An adhesive layer is formed on the polyurethane foam sheet side if the formed laminate comprising the polyvinyl chloride sheet and the polyurethane foam sheet.
(6) A resin aggregate having a predetermined shape is formed by the heat-forming method such as vacuum forming or air-pressure forming.
(7) The polyvinyl chloride sheet/polyurethane foam sheet laminate is preliminarily heated and placed on the resin aggregate formed body, and the assembly is heat-molded and integrated.
As is apparent from the foregoing description, the conventional laminate to be used for interior automotive trims is defective in that the preparation steps are much complicated.
Furthermore, since this laminate comprises a soft polyvinyl chloride sheet containing a plasticizer, as pointed out hereinbefore, the laminate is disadvantageous in that the surface is soft and sticky and the atmosphere in an automobile becomes blurred.